146 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1944 
time. Figure 16 shows how necessary it is in such a long term 
of years to select the exact period. Using 8 months there is but small 
amplitude, even when seasonal influences are eliminated, but with 
EAE 
| Ashes 
ST De is 
iS 
/CA t 
ALIWAL, S.AFR. 
4 
bs 
zz 
MONTHS OF YEAR 
Fiaure 15.—Phase relations of periodicities in terrestrial responses to solar variations, depending on seasons of the 
> a wn » ™ ~ > gD N » %) > 
COl#7d SO SHLNOW 
8/4 months all three stations show a strong periodicity, with ampli- 
tudes of 1°.3 C., 1°.1 C., and 1°.3 F., respectively, over nearly a cen- 
tury and a half. In this way we have been able, by using tempera- 
year, 
